Presumably the reason you can’t wear a cup in competition is the advantage it gives you when doing armbars: By having the cup as a fulcrum for the elbow, you can apply force with a smaller range of motion, and with poorer form (that is, you can finish an armbar more easily even if you don’t properly pinch your knees together).

As such, I know that if I were rolling with a beginner, I’d be much happier if they didn’t wear a cup. In the beginning you won’t know just how far or fast to go when applying joint locks; accidents happen and most often they happen due to the innocent ignorance and inexperience of white belts. A cup gives less margin of error and makes me—your hypothetical training partner—more likely to get injured.

Anyway, you should learn to roll without a cup because as CrackFox mentioned, you can’t wear them in competition; and because without one, you’ll be forced to develop better habits (pinching your knees together to control the opponent’s limbs).

I think the ban on wearing cups in BJJ competion is just silly, but then again this comes from an organization that doesn't consider a body triangle as a form of back control, is aghast at the thought of pulling the head down in a triangle, and believes the kneebar and straight Achilles lock are the equivalent of taping broken glass to your hands before rolling. At the rate they are going, BJJ competitons rules will soon be even more incomprehensible than the ones governing judo tournaments, and won't that be a barrel of laughs.

OP, go ahead and wear a cup in your training. It protects vulnerable parts of your body from people enthusiastically applying knee through the middle guard passes or any number of reaping throws or inside leg trips. I wouldn't go to the gym to clean mats off without slipping mine on, and I've never regretted having it on. I've never really bothered with a specific brand, the over the counter type I can purchase at Academy or Hibbet has never let me down so far (knocks on wood).

And as for the gentlemen claiming that one should train without a cup because you can't wear one in competition and it will build better habits (at the cost of taking damage to vulnerable body parts) would you also advise an aspiring boxer or Muay Thai fighter to train without headgear because he can't wear it in competition, and the lack of protection on his skull will encourage him to develope better dodging/blocking skills?

I think the ban on wearing cups in BJJ competion is just silly, but then again this comes from an organization that doesn't consider a body triangle as a form of back control, is aghast at the thought of pulling the head down in a triangle, and believes the kneebar and straight Achilles lock are the equivalent of taping broken glass to your hands before rolling.

Are we talking IBJJF here? If so, I believe you are mistaken on three out of four counts: I agree with the silliness of body triangles not counting as back control, but pulling the head down in triangles is allowed (except for juniors under the age of 16), kneebars are allowed (albeit only in brown and black belt divisions), and straight Achilles locks are allowed (except for juniors under 16).

And as for the gentlemen claiming that one should train without a cup because you can't wear one in competition and it will build better habits (at the cost of taking damage to vulnerable body parts) would you also advise an aspiring boxer or Muay Thai fighter to train without headgear because he can't wear it in competition, and the lack of protection on his skull will encourage him to develope better dodging/blocking skills?

That’s a ridiculous comparison. I’ve trained BJJ for 4½ years and taken a grand total of a dozen or so accidental nut shots, zero of which were bad, and have sustained no actual damage to vulnerable body parts. (Well, not those body parts, anyway.) I tend not to be bothered by down-the-middle guard passes (possibly because I have a habit of squeezing my knees together to control the limb). If you train boxing or Muay Thai, the head shots will be frequent and intentional.

The only real damage to the testicles I’ve even heard of in a grappling context is from a botched uchimata; in judo, not BJJ.

...ummm. Whether or not you train with or without a cup is an entirley personal decision.

Me, if I don't have a cup, I'd rather sit off to the side than roll. I literally feel naked if I'm on the mats without a cup and feel uncomfortable as hell.

Any tourney that is run with strict adhereance to IBJJF Rules will not allow you to wear a hardened cup. Which is is completley asinine where their reasoning is that wearing a cup increases the likelihood of causing injury to the opponent AND/OR the competitor.

Check the rules for any other tournament you are going to compete in. For example, NAGA "encourages" competitors to wear groin protection. I beleive both Grapplers Quest and COPA do as well. Check the rules for the tourney.

In just about 7 years of training and competing in BJJ, both gi and no-gi, I HAVE NEVER BEEN SUBMITTED DUE TO MY OPPONENT'S CUP.

Sure, positionally, the cup can be an irritant at times to both people (front or back mount with extended grapevines, kimura transitions from top control, etc.). If you have been grapplling for more than 3 months you simply get used to it. With regard to having "more leverage" on an arm-bar, 9 times out of 10, you don't finish the arm bar without some sort of minimal scramble by your opponent trying to counter, the very shape of the cup results in the arm sliding to one side or the other before the sub is finished anyway.

Even if you are applying the textbook armbar from mount, going to s-mount, securing the arm, pushing the head, stepping over sitting partially on the shoulder, and falling back while pinching the arm tight with your knees, the leverage added by the cup has no bearing on when the tap comes as the arm will likeley NOT be sitting squarley on the front of the cup. Its a rediculious argument and in my opinion a rediculious rule that puts you in much more danger of injury than not wearing one.

Competition aside. Get a good pair of compression shorts or else your training rolls will consistently be paused by...."oooooh....my nuts....gimmie a sec (pant, pant, pant)".

I use my cup as a weapon all the time. Mount -> grapevine -> superman. Drives the cup into the solar plexus. Helps me get high mount. I also will knee ride your balls like teacups at the carnival if I find someone not wearing a cup in training.

Are we talking IBJJF here? If so, I believe you are mistaken on three out of four counts: I agree with the silliness of body triangles not counting as back control, but pulling the head down in triangles is allowed (except for juniors under the age of 16), kneebars are allowed (albeit only in brown and black belt divisions), and straight Achilles locks are allowed (except for juniors under 16).

In my defense, I am almost certain that the head pulling triangle was banned at one point (and yes, I am aware that with proper form the choker should latch onto his or her own shin, not the chokee's head, but it's the principle of the thing).

As for how my thoughts on all lower body submissions save the Achilles being barred until brown and black belt (not to mention the restrictions put on how the Achilles can be performed) well that topic could easily have it's own thread, let's just say that I disagree. Strongly.

Moving on to actual on topic anecdotes, when I was first starting out in Brazilian Jiu Jitsu I absorbed a truly excruciating one off of a single leg takedown (imagine a 200 pound guy dropping from a standing position right onto a prone person's "vulnerables" leading with the point of his knee). True, this was a one time event, but the chance that it could happen again has led to me loading my plastic protection into my gear bag even before my gi top and belt.

I look at it like car insurance. Certainly I am not regularly involved in fiery crashes, and I don't know many people who are, but even the possiblity that it might happen and the serious repercussions if it does are enough to make me shell out for that extra bit of self protection.

Yes, I'm aware that when I post in reply to you I adopt a pseudo intellectual tone and verbiage that looks like I swallowed a thesarus and then got punched in the stomach. It bothers me too.